Rotary regenerative heat exchange apparatus



Nov. 9, 1965 J. CONDE 3,216,488

ROTARY REGENERATIVE HEAT EXCHANGE APPARATUS Filed Nov. 23, 1962 m 28 V I? INVENTOR. James Cona'e' United States Patent 3,216,488 ROTARY REGENERATIVE HEAT EXCHANGE APPARATUS James Conde, Wellsville, N.Y., assignor, by mesne assignments, to The Air Preheater Company, Inc., a corporation of Delaware Filed Nov. 23, 1962, Ser. No. 239,423 4 Claims. (Cl. 165-9) The present invention relates to improvements in regenerative heat exchange apparatus of the rotary type and particularly to an arrangement that minimizes thermal distortion of the several relatively movable parts so as to provide an optimum sealing relationship therebetween.

In regenerative heat exchange apparatus of the rotary type, a cylindrical rotor having compartments carrying mass of heat absorbent material is first exposed to a stream of hot gas or other heating fluid and then to a stream of cooler air or other fluid to be heated whereby heat absorbed from the gas may be imparted to the air. The rotor is surrounded by a housing including end or sector plates having spaced openings that provide for the flow of gas and air. To prevent mingling of the gas and air, radial partitions which form the compartments are provided with radial seals which wipe against or otherwise cooperate with the imperforate portion of the sector plates in a predetermined manner.

The problem of sealing between air and gas passageways becomes especially difficult in heat exchangers of large dimensions where thermal distortion is extensive and where the difference in pressure between air and gas streams is usually great.

The present invention contemplates an improved form of heat exchanger wherein the sealing means and the sector plate adjacent thereto are adapted to direct their thermal expansion along parallel planes to preclude mutual interference therebetween, and the invention will be best understood upon consideration of the following detailed description of an illustrative embodiment thereof when read in conjunction with the accompanying drawings in which:

FIGURE 1 is a sectional elevation of the rotary regenerative heat exchanger showing the several parts in their proper relationship, and

FIGURE 2 is a top plan view of the heat exchanger.

Referring to FIGURE 1 of the drawing, the rotor comprises a central rotor post joined to a concentric rotor shell 12 by radial partitions 14 to provide a series of sectorial compartments 16 therebetween. The compartments are adapted to carry a mass of perforate heat absorbent material through which hot gas and cold air are alternately directed.

The rotor is surrounded by a rotor housing 18 having apertured end or sector plates 22 and 24 connected to suitable ductwork 26 and 28 that directs the flow of air and gas through the rotor in a counterfiow relation.

The rotor is rotatably mounted on a support bearing 32 that is carried by a support beam 34 at the cold end of the rotor, the name commonly given the end of the apparatus lying adjacent the entrance for the cold air. The opposite or hot end of the rotor is mounted in a guide bearing 36 that is in turn mounted on the guide beam 37 that bears upon beam 34. The bearing 36 precludes lateral displacement but is adapted to permit axial expansion and contraction of the rotor in accordance with thermal variations.

The radial inner end of each end plate 22, 24 is slidably carried by a slip joint which is supported from its adjacent beam 34 or 37 by a center spool 44. The outer end of each plate is fixedly secured to the rotor housing 18 and to its related duct structure in order that thermal expansion of the end plate will be directed radially into the slip joint to preclude any axial distortion thereof. Inasmuch as the slip joints in spools 44 are sized to provide adequate space for expansion and contraction of the mating end plate, the end plates expand lineally without the usually attendant distortion so as to maintain a continuously plane sealing surface with which the sealing surfaces on the end edges of the radial partitions may cooperate.

The sealing means that extend radially at the hot end of the rotor are of the type commonly termed cantilever seals. Such seals are carried by a radial beam 46 that is fixedly secured to the rotor post and is unattached, except by slip joints 48 to the adjacent radial partition in order that any expansion and contraction of the radial beam will be directed radially only and will not distort or otherwise atfect the sealing relationship between the seal 45 and its adjacent end plate. Under certain conditions it may be advantageous to secure the radial seals 45 directly to the radial partition and make adjustments in setting that compensate for rotor distortion. This arrangement is shown by radial seals 50 at the cold end of the rotor. The rotor distortion generally present is in the form known as rotor dishing which occurs when a thermal gradient is impressed across the rotor, and the rotor is forced to assume the shape of a frustum of a cone with the hot end larger in diameter and convex while the cold end is smaller and concave.

Axial sealing means 30 extend through the plenum chamber 35 between the imperforate portions of axially spaced end plates 22 and 24. The sealing means 30 are preferably adapted to be adjusted during normal operation from a location outside the rotor housing whereby an optimum relationship between the seals and the periphery of the rotor may be obtained to preclude the circumferential flow of fluid through the chamber 35 around the rotor.

The spacing relationship between the ends of the rotor and the adjacent rotor housing varies continuously with the heating of the rotor. This is due chiefly because the lineal expansion along the axis of the rotor is greater than that of the surrounding housing since it has a greater average temperature, and the rotor is thereby displaced in a direction away from its support bearing and in a direction that moves it toward its cooperating guide bearing at the hot end of the rotor.

To use this relationship to an advantage in providing maximum sealing benefits to the apparatus, the cold end of the rotor carried by support bearing 32 is located during assembly closely adjacent end plate 24. By contrast the hot end of the rotor is spaced from its adjacent end plate 22 a distance that is determined by the amount of expansion inherent for the rise in temperature expected. Thus by locating the fixed or cold end of the rotor closely spaced in a predetermined sealing relation with its adjacent end plate while the hot end of the rotor is spaced a greater distance from its adjacent end plate, axial expansion of the rotor may be utilized to move the hot end seal into a preferred sealing relationship during normal operating conditions.

Since the radial sealing members are adapted to lie in a plane substantially parallel to their adjacent end plates, an ideal sealing relationship is naturally obtained, and axial growth of the rotor due to an increase of temperature may be eifectively used to move the hot end seal into a preferred spacing relationship with its adjacent end plate whereby there will be a minimum of fluid leakage therebetween.

While this invention has thus been described with reference to the embodiment illustrated in the drawing, it is evident that various changes may be made in the specific design without departing from the spirit of the invention. It is therefore intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

I claim:

1. Rotary regenerative heat exchange apparatus for the transfer of heat between a heating fluid and a fluid to be heated comprising a rotor having a central rotor post and a concentric rotor shell, radial partitions, extending between the rotor post and rotor shell to provide a series of sectorial compartments therebetween, a mass of heat absorbent material carried by the compartments of the rotor, cylindrical housing means surrounding the rotor having end plates at opposite ends thereof with imperforate portions between spaced apertures that direct the heating fluid and the fluid to be heated through the compartments of the rotor, inlet and outlet ducts directing the fluids to said apertures, a support beam, a bearing carried by said support beam supporting the rotor in fixed relation to its adjacent end plate, a guide beam at the spaced end of said rotor, a guide bearing carried by said beam to preclude radial displacement of the rotor, means carried by said beams at opposite ends of the rotor to slidably support the inner ends of end plates adjacent thereto, and radial sealing means at each end of the rotor lying, parallel to adjacent end plates when the rotor is subjected to the flow of fluid therethrough.

2. Rotary regenerative heat exchange apparatus for the transfer of heat between a heating fluid and a fluid to be heated comprising a rotor having a central rotor post and a concentric rotor shell joined together by radial partitions to form a series of sector-shaped compartments therebetween, 3, mass of heat absorbent material carried. by the compartments of the rotor, cylindrical housing means surrounding the rotor including end plates at opposite ends thereof having imperforate portions between spaced apertures that direct the heating fluid and the fluid to be heated through the rotor in a counter flow relation, means securing the end plates continuously to the outer periphery of the rotor housing, means adjacent the rotor post slidably supporting the radial inner end of each end plate independently of said housing, inlet and outlet ducts for said fluids leading to the apertures for said housing, a support bearing at the end of the rotor adjacent the inlet for the fluid to be heated rotatably supporting the rotor in fixed relation to its adjacent end plate, a guide bearing radially supporting the opposite end of said rotor While permitting axial movement thereof, means at each end of the rotor supporting an adjacent end plate to permit its unencumbered radial expansion and contraction, and radial sealing means at the ends of said radial partitions lying in sealing relation with said end plates.

3. Rotary regenerative heat exchange apparatus as defined in claim 2 wherein the means slidably supporting said end plates comprise spool-like members that surround the rotor post.

4. Rotary regenerative heat exchange apparatus for the transfer of heat between a heating fluid and a fluid to be heated having .a rotor with a central rotor post and a concentric rotor shell joined together by radial partitions to form a series of sector-shaped compartments therebetween, and a mass of heat absorbent material carried by the compartments of the rotor, and a cylindrical housing surrounding the rotor including end plates at opposite ends thereof having imperforate portions between spaced apertures that direct the, heating fluid and the fluid to be heated through the rotor in counterflow relation, meansv rotatably supporting the end of the rotor adjacent the inlet for the fluid to be heated in fixed-relation to its adjacent end plate, means supporting the opposite end of the rotor against radial displacement While permitting axial movement thereof in response to thermal variations of said rotor post, means supporting each end plate independent from said housing to permit. freedom of radial expansion, and sealing means carried by the rotor movable axially into a predetermined sealing arrangement with the end plate at the end of the rotor adjacent the inlet for the heating fluid, said sealing means being supported on beams carried by the rotor post and extending radially outward therefromto preclude fluid flow between the rotor and its adjacent end plate.

References Cited by the Examiner 1 UNITED STATES PATENTS 2,229,691 1/41 Boestad l9 2,732,184 1/56 Ballard et al l6510 3,095,036 6/63 Teufel l659 CHARLES SUKALO, Primary Examiner. 

1. ROTARY REGENERATIVE HEAT EXCHANGE APPARATUS FOR THE TRANSFER OF HEAT BETWEEN A HEATING FLUID AND A FLUID TO BE HEATED COMPRISING A ROTOR HAVING A CENTRAL ROTOR POST AND A CONCENTRIC ROTOR SHELL, RADIAL PARTITIONS, EXTENDING BETWEEN THE ROTOR POST AND ROTOR SHELL TO PROVIDE A SERIES OF SECTORIAL COMPARTMENTS THEREBETWEEN, A MASS OF HEAT ABSORBENT MATERIAL CARRIED BY THE COMPARTMENTS OF THE ROTOR, CYLINDRICAL HOUSING MEANS SURROUNDING THE ROTOR HAVING END PLATES AT OPPOSITE ENDS THEREOF WITH IMPERFORATE PORTIONS BETWEEN SPACED APERTURES THAT DIRECT THE HEATING FLUID AND THE FLUID TO BE HEATED THROUGH THE COMPARTMENTS OF THE ROTOR, INLET AND OUTLET DUCTS DIRECTING THE FLUIDS TO SAID APERTURES, A SUPPORT BEAM, A BEARING CARRIED BY SAID SUPPORT BEAM SUPPORTING THE ROTOR IN FIXED RELATION TO ITS ADJACENT END PLATE, A GUIDE BEAM AT THE SPACED END OF SAID ROTOR, A GUIDE BEARING CARRIED BY SAID BEAM TO PRECLUDE RADIAL DISPLACEMENT OF THE ROTOR, MEANS CARRIED BY SAID BEAMS AT OPPOSITE ENDS OF THE ROTOR TO SLIDABLY SUPPORT THE INNER ENDS OF END PLATES ADJACENT THERETO, AND RADIAL SEALING MEANS AT EACH END OF THE ROTOR LYING PARALLEL TO ADJACENT END PLATES WHEN THE ROTOR IS SUBJECTED TO THE FLOW OF FLUID THERETHROUGH. 